1. Field of Invention
Embodiments of the present invention generally relate to semiconductor devices and methods of fabricating the same. More particularly, embodiments of the present invention relate to a semiconductor device and a method of fabricating the same having increased reliability.
2. Description of the Related Art
Generally, a semiconductor device can be fabricated through a fabrication process of forming cells having integrated circuits by repeatedly forming a circuit pattern on a substrate, and an assembly process of packaging the substrate, on which the cells are formed, into chips.
Further, an Electrical Die Sorting (EDS) process of testing the electrical properties of the cells formed on the substrate can be performed between the fabrication process and the assembly process. Bad cells on the substrate are sorted through the EDS process. Here, the sorted bad cells are replaced with previously fabricated redundant cells in a repair process, thereby increasing the yield of the semiconductor device because operation is normal at the time of actual chip operation.
The repair process can be performed by applying a laser beam to wires connected to the bad cells and cutting the wires. In this case, the wires to be cut by the laser beam are referred to as fuses, and the region in which the fuses are clustered close together is referred to as a fuse region. A fuse window for opening fuses is formed under insulation films in the fuse region. When the fuse window is formed, a predetermined number of the fuses located under interlayer dielectric film are also etched, thus determining the thickness of the fuses.
However, as the amount of etching of fuses increases when the fuse window is formed, the thickness of the fuses decreases. As a result, neighboring fuses can be damaged during the repair process. In contrast, when the amount of etching of fuses decreases, the thickness of the fuses increases. As a result, the fuses cannot be completely cut during the repair process. Accordingly, a method of forming a monitoring pattern for monitoring the thickness of the fuses is being sought.
However, if a monitoring pattern is formed in a shape resembling a flat plate, the insulation film cannot be formed to a substantially uniform thickness when the insulation film is deposited on the fuses and the monitoring pattern. For example, the insulation film might be more thickly formed at the center of the monitoring pattern than at peripheral regions thereof. If the thickness of the insulation film on the fuses and the monitoring pattern is not substantially uniform, then the degree to which the insulation film is etched is different at the time of formation of the fuse window and the monitoring window. As a result, the residual thicknesses of the fuses and the monitoring pattern are also different. Accordingly, the thickness of the fuses cannot be accurately monitored.